Dawkins blows the doors off inherited assumptions about religion and its place in our lives. He wants to create a "coming out" for atheists and arm them with strong arguments against the inevitable backlash such a coming out would engender.
I think Dawkins does a great job cutting through cultural expectations and assumptions and offering ready-made platforms for those who feel unsteady standing up for their beliefs (or lack of beliefs). As a result of going after that goal, the book is a little reactionary. Instead of calmly and elegantly building a thesis on why religion holds the place in our society that it does, and what place Dawkins thinks religion should have in our future, he jumps around from argument to argument a little, fending off naysayers and attackers typical of those he's dealt with in the past.
The God Delusion is good at what it set out to do- passionately defend atheism and revolutionize the attitude we have toward religion.